Effects of prenatal PPAR-γ agonist rosiglitazone exposure on rat hippocampus development in a time-dependent manner: A stereological and histopathological study.

Rosiglitazone is in the thiazolidinedione class of drugs used in the treatment of type 2 diabetes mellitus. It works as an insulin sensitizer by binding to the peroxisome proliferator-activated receptor gamma. We investigated the effects of prenatally administered rosiglitazone on pyramidal cell numbers and morphologies in the hippocampus at postnatal period using histochemical and stereological techniques, congenital morphological properties and the number of offspring in rats. Eighteen female rats were grouped into control (C), low-dose rosiglitazone (LDR) and high-dose rosiglitazone (HDR). LDR pregnant rats received 2 mg/kg/day of rosiglitazone via oral gavage during the first 16 days of the pregnancy. HDR rats received 5 mg/kg/day. The infants were grouped into newborn (NB), 4 week (4 W) and 12 week (12 W). A side from histopathologic and congenital assessments, stereological analyses were performed using the optical fractionator method. Congenital anomaly was not detected in any of the rosiglitazone treatment groups, and their number of offspring was similar to that of the C group. Stereological counts revealed a significant reduction in the number of hippocampal pyramidal cells in the C and LDR groups but not in the HDR group until birth to 12th week. When NB groups were compared, the number of pyramidal cells in the HDRNB group was less than those in the LDRNB and CNB groups. HDR affected apoptosis or the proliferation and maturation of progenitor cells to the pyramidal neuron during neurodevelopment in the hippocampus, whereas LDR did not adversely affect neuronal development and did not cause congenital anomalies.

Antioxidant and renoprotective effects of paricalcitol on experimental contrast-induced nephropathy model.

OBJECTIVES: The aim of the study was to assess the effect of paricalcitol on the experimental contrast-induced nephropathy (CIN) model. We hypothesised that paricalcitol may prevent CIN. METHODS: 32 Wistar albino rats were divided into four groups (n=8 each): control group, paricalcitol group, CIN group and paricalcitol plus CIN group. Paricalcitol (0.4 µg kg(-1) day(-1)) was given intraperitoneally for 5 consecutive days prior to induction of CIN. CIN was induced at day 4 by intravenous injection of indometacin (10 mg kg(-1)), Nω-nitro-L-arginine methyl ester (L-NAME, 10 mg kg(-1)) and meglumine amidotrizoate (6 ml kg(-1)). Renal function parameters, oxidative stress biomarkers, histopathological findings and vascular endothelial growth factor (VEGF) immunoexpression were evaluated. RESULTS: The paricalcitol plus CIN group had lower mean serum creatinine levels (p=0.034) as well as higher creatinine clearance (p=0.042) than the CIN group. Serum malondialdehyde and kidney thiobarbituric acid-reacting substances levels were significantly lower in the paricalcitol plus CIN group than in the CIN group (p=0.024 and p=0.042, respectively). The mean scores of tubular necrosis (p=0.024), proteinaceous casts (p=0.038), medullary congestion (p=0.035) and VEGF immunoexpression (p=0.018) in the paricalcitol plus CIN group were also significantly lower. CONCLUSION: This study demonstrates the protective effect of paricalcitol in the prevention of CIN in an experimental model.

JC virus-associated nephropathy in a renal transplant recipient and comparative analysis of previous cases.

We report JC virus (JCV)-associated nephropathy in a renal allograft recipient and summarize the clinical and laboratory data of the 8 previous cases. A 28-year-old male renal allograft recipient received a preemptive transplant from his father. Six months later, a kidney biopsy was performed because of deterioration of allograft function. Biopsy revealed tubulointerstitial mononuclear infiltrates with normal glomeruli; on hematoxylin and eosin staining, basophilic nuclear inclusions were seen in the nucleus of tubular cells. Urinary cytology failed to demonstrate decoy cells, but polymerase chain reaction of a urinary sample was positive for JCV 3.15 × 10(10) copies/mL. Additionally, polyomavirus (SV40) immunohistochemical staining was performed and was positive in the enlarged nuclei of tubular epithelial cells in the kidney biopsy sample. After the diagnosis of polyomavirus-associated nephropathy (PVAN) was confirmed by kidney biopsy, immunosuppressive agents were reduced. Intravenous immunoglobulin was administered 5 times at a dose of 500 mg/kg every other 3 weeks. Two months after diagnosis, the serum creatinine became stable and urinary viral load of JCV was decreased. Because viruria was still present, tacrolimus was converted to sirolimus. Four months after immunosuppressive agent conversion from tacrolimus to sirolimus, the viruria had disappeared. Review of the literature and our case demonstrates that male gender, previous acute rejection episode, low incidence of JCV viremia, PVAN pattern B histology, and reducing immunosuppression are the diagnostic touchstones for PVAN due to JCV.